Drying garments



June 28, 1966 T. H. WENTZ DRYING GARMENTS 2 Sheets-Sheet 1 Filed Aug. 28, 1963 FIGI.

FIGS.

mvcwron: THEODORE H. WENTZ ATTYS June 28, 1966 T. H. WENTZ DRYING GARMENTS 2 Sheets-Sheet 2 Filed Aug. 28, 1965 m OE INVENTOR; BY THEQDORE H. WENTZ W W ATTYS,

for drying washed fabrics.

United States Patent 3,257,739 DRYING GARMENTS Theodore H. Wentz, Villauova, Pa., assignor to Proctor & Schwartz, Inc, Philadelphia, Pa., a corporation of Pennsylvania Filed Aug. 28, 1%3, Ser. No. 305,143 7 Claims. (Cl. 3431) The present invention relates to method and apparatus More particularly the present invention relates to a method and apparatus for drying washed fabrics comprised of a yarn made up at least in part of fibers which are thermoplastic in nature.

A typical fabric of the above type is one wherein the yarns are comprised of a polymer such as Dacron and a natural fiber such as cotton. Various types of garments are made of such a fabric including, for example, waiter and barber coats and also uniforms worn by nurses and hairdressers. These garments usually are laundered by washing them in a heated wash water including a detergent wherein the temperature of the wash water is maintained at approximately 160 F. or higher to effectively remove dirt and stains. During washing of the garments, the elevated temperature of the wash Water and the tumbling of the garment in the confined area of a washing machine, causes the garments to wrinkle. This wrinkling is due to the action of thermoplastic fibers which when heated to the wash temperature, are angularly deformed and which characteristically when the garment is dried, tend to set in an angularly deformed condition. At present, after the garments are washed and dried, the garments are pressed to remove wrinkles. In

accordance with most high-speed pressing methods, the

dried or semidried garment is dressed on a form or dummy and then pressed with conventional ironing apparatus. In order to simplify ironing of the garment, the fashion of the garment is usually very simple having a minimum of pleats and overlap areas. However, even when great care is exercised in the ironing process, portions of the garment which are of double or triple thickness, as for example seams, collars, button and buttonhole strips,

are difiicult to iron in a manner to remove all wrinkles.

The present invention provides a novel method and apparatus for drying washed garments of the above type so that they are in a substantially wrinkle-free condition ready for wear without having to iron the same to press out wrinkles in the garments resulting from washing. To this end, the washed garments are subjected to a drying medium, the condition of which is controlled in a predetermined manner in relation to the character of the thermoplastic fibers in the fabric of the garment and the temperature of the wash water. More specifically in accordance with the present invention, the wet bulb temperature of the drying medium is maintained at a temperature higher than the temperature of the wash water and the dry bulb temperature of the drying medium is maintained at a slightly higher temperature than the Wet bulb temperature. By this method, it has been found that after a predetermined drying time, the angular deformation of the thermoplastic fibers in the garment resulting from washing is removed and the garment assumes a substantially wrinkle-free condition.

In view of the above, it is readily apparent that laundering garments in accordance with the present invention is more economical and less time consuming by reasons of the fact that dressing and undressing of garments on forms or dummies and the tedious process of ironing the same is eliminated. Moreover, in accordance with the present invention, the entire garment, including the troublesome portions thereof which are of double or triple thicknesses, is substantially wrinkle free. Further Patented June 28, 1966 ice by reason of the present invention, it is now possible to fashion garments of the above type to include more pleats or overlapping areas since the ironing problem here tofore present, is eliminated. Moreover the life of the garments of this type is extended considerably by eliminating the ironing process.

Other objects of the present invention and the various features and more specific details of the operation of the method and the construction of apparatus in accordance with the present invention are hereinafter more fully set forth with reference to the drawings, in which:

FIG. 1 is a plan view partly in section of apparatus in accordance with the present invention;

FIG. 2 is an enlarged sectional view taken on line 2-2 of FIG. 1; and

FIG. 3 is a chart of fabric temperature and time in dryer for a particular fabric dried in apparatus according to'the present invention.

Referring now to the drawings, there is illustrated a drying apparatus 14) constructed in accordance with the present invention. The apparatus may comprise several adjacent sections A and B illustrated in FIG. 1 which are mounted in end to end relation. The garments G to be dried are suspended from hangers H engageable on hooks depending at spacedlocations from a conventional endless conveyor C which transports the garments through the dryer 10 in the direction indicated in FIG. 1. Suitable curtain means or the like (not shown) is provided at the entrance and discharge ends of the dryer to minimize leakage into or out of the dryer at the inlet and discharge ends as the garments G to be dried, pass through the dryer.

In the drawings, only the dryer section A is illustrated in detail, the additional sections if desired being of a similar construction. Section A as illustrated, comprises a housing or enclosure 16 including a top wall 18, confronting opposite end walls 20 and 22 and opposing side walls 24 and 26. The interior of the housing 16 is subdivided into several compartments or zones including a drying chamber 30 extending lengthwise of the dryer and which as illustrated in FIG. 2 is defined by a vertical partition 32 parallel and spaced from the side wall 26 and spaced upper and lower foraminous partitions 34 and 36. The upper partition 34 is spaced below the top wall 18 to define, in the present instance, a drying medium exhaust manifold above the drying chamber 30 and the lower partition 36 is spaced above the bottom wall of the housing to define a drying medium inlet manifold 42 below the drying chamber 30.

Means is provided for circulating the drying medium through the drying chamber 30 comprising a fan which communicates with the manifolds 40 and 42 to suck or draw the drying medium from the exhaust mani fold 40 and discharge it to the inlet manifold 42. The fan 50 is driven by suitable drive means such as a motor 52 mounted exteriorly of the dryer and connected to the shaft of the fan by suitable belt transmission means. As illustrated, the fan 50 is mounted in a hood structure 53 adjacent the side of the dryer section opposite the drying chamber 30. The hood structure 53 includes a vertical wall 55 having an opening 57 therein with-in which the cowl defining the intake of the fan is mounted and a leg portion 59 connecting the discharge side of the fan 50 with the inlet manifold 42.

In accordance with the present invention, means is provided for selectively controlling the condition of the drying medium circulated through the drying chamber 30 so that the wet bulb temperature of the drying medium in the drying chamber 30 is maintained higher than the temperature of the wash water in which the garments G were washed and the dry bulb temperature of the drying medium is maintained at a temperature slightly higher than the wet bulb temperature of the drying medium. To this end there is provided a drying medium conditioning chamber 60 communicating with the exhaust manifold and the intake side of the fan and means in the chamber for conditioning the drying medium including heating means for controlling selectively the dry bulb temperature of the drying medium and a spray unit 7%) operable to selectively add moisture to the drying medium for selectively controlling the wet bulb temperature of the drying medium. In the present instance, the heating means comprises a plurality of heating coils 62 adjacent to the top of the conditioning chamber 60 and inlet and outlet conduits 64 and 66 for circulating a heating medium, such as steam therethrough, the inlet conduit 64 having valve means for selectively controlling the rate of steam flow through the heating coils. In the present instance, a fine mesh screen 67 is provided at th inlet side of the conditioning chamber 60 to filter out lint and other particles entrained in the drying medium. The spray unit 70 has conduit means 72 for delivering Water or steam to the unit and a valve control 74 for selectively controlling the amount of water or steam dispensed by the unit.

Sensing means in the form of a hygrometer is provided in the hood structure 53 downstream of the discharge side of the fan to measure the dry bulb and wet bulb temperatures of the drying medium delivered to the drying chamber 30. The hygrometer 80 is connected through suitable leads to a control device 81 exteriorly of the dryer housing which device is in turn operatively connected to the valves 65 and 74 for selectively regulating amount of heat and moisture imparted to the drying medium for a given setting of the control device. By this arrangement, the control device 81 may be set to regulate the heating means and spray unit to selectively increase or decrease the amount of heat and/or moisture add d to the drying medium when the dry 'bul b and/or wet bulb temperature of the drying medium as sensed by the hygrometer 8t) vary from their respective predetermined values.

For example, if the wet bulb temperature of the drying medium is abov the predetermined value as sensed by the hygrometer 80, the control device 81 is signalled and operates the valve 74 to reduce the amount of moisture added to the drying medium. Conversely, if the wet bulb temperature of the drying medium is less :than the predetermined value, the control device 81 effects operation of the valve 74 to increase the amount of moisture added to the drying medium to raise the wet bulb temperature to the predetermined value. Further if the dry bulb temperature of the drying medium is greater than the predetermined value as sensed by the hygrometer 30, the control device 81 is signalled to effect actuation of the valve 65 to decrease fiow through the heating coils 62 until the dry bulb temperature is brought down to the predetermined value. If the dry bulb temperature is less than the predetermined value, the control device 81 is signalled through the hygrometer 80 to increase flow through the heating coils 62 to raise the dry bul-b temperature to the predetermined value.

Tracing now the flow pattern of the drying medium through the dryer and starting at the exhaust manifold 40, drying medium circulated through the drying chamber enters the exhaust manifold 40 and is drawn through the conditioning chamber 60 by the fan 50. An outlet 82 may 'be provided in the exhaust manifold 40 which has a damper 84 selectively adjustable to vent some of the drying medium to the atmosphere. The fan 50 discharges the drying medium through the leg portion of the hood 53 to the air inlet manifold. The hygrometer 80 measures the condition of the drying medium and if the dry =bulb and/or wet bulb temperature of the drying medium vary from the selected settings on the control device 81, the control device effects actuation of th control valve 65 for the heating coils and/or the control valve 74 for the spray unit to compensate for deviation from the selected conditions. By this arrangement, the medium circulated through the drying chamber may be maintained at a preselected substantially uniform dry and wet bulb temperature whereby when the garments G have been in the drying chamber a predetermined length of time, they are dried to a substantially Wrinkle-free condition.

Operation of the dryer is further illustrated, but not limited, by the following example. Coats made of a fabric comprising 65% Dacron and 35% cotton were washed in a wash water having a temperature of about F. After washing, the coats which have a moisture content in the vicinity of 83% BDB were placed on hangers and suspended from the conveyor C and then run through the dryer. The control device 81 was set to effect circulation of a drying medium through the drying chamber 30 having a wet bulb temperature slightly higher than the wash temperature of the garments about F. and a dry bulb higher than the wet bulb temperature about 225 F. It is noted that the dry bulb temperature should be lower than the degradation temperature of the thermoplastic fibers. Under these conditions, the drying medium was circulated through the drying chamber 30 upwardly through the coats, the air circulation in the chamber being in the neighborhood of 300 feet per minute. The circulation of drying medium upwardly through the garments in this velocity range effects agitation and ballooning of the garments thereby enhancing drying thereof to a wrinkle free condition. It is noted that by subjecting the garments G to moist heat the temperature of the garment is raised quickly from about 70 F. when it enters the dryer to a temperature of about 175 R, which is above the wash temperature, whereby the set in the thermoplastic fibers put in during the wash operation may be removed (see chart in FIG. 3). It is noted that the temperature of the garments drops from about 160, the temperature of the wash water, to about 70 during the time the garments are removed from the washer, are permitted to drip dry a short period of time and are then conveyed through the drying apparatus. Further, it is noted that the garments G stay at approximately 175 for approximately eight minutes during movement through the drying apparatus, during which time the fre moisture is removed from the garments. In this manner, the wet bulb temperature of the fibers of the garment are in a desiredv condition for wrinkle removal. After the free moisture is removed, the temperature of the garments gradually rises as shown on the chart in FIG. 3. When the garments had been subjected to a drying medium in the drying chamber a predetermined length of time, about 13 to 15 minutes, the temperature of the material in the garment was approximately 220 as shown on the chart in FIG. 3, and the garment had dried to a substantially wrinkle-free condition. After the garments are discharged from the dryer, they are permitted to cool before being removed from the hangers H.

The basic concept of the present invention for drying fabrics to a substantially wrinkle-free condition resides 1n subjecting freely suspended fabrics to a drying medium wherein the wet bulb temperature of the drying medium is maintained above the temperature in which the fabric was washed and the dry bulb temperature of the drying medium is maintained above the web bulb temperature. By this procedure of subjecting fabric'to moist heat, the temperature of the fabric is raised quickly above the wash temperature to place the thermoplastic fibers of the fabric in a condition to overcome angular deformation which manifests itself as Wrinkles. Agitation of the suspended fabric in the present instance by directing drying medium upwardly through the garments causing ballooning thereof also aids in wrinkle removal. It is noted that heavier fabrics tend to dewrinkle very well. Further by maintaining the dry bu-lb temperature of the drying medium above the wet bulb temperature, the free and bound moisture of the fabric is removed during the drying operation.

It is noted that the principle of operation of the present invention is not limited to the example noted above, but to any fabric comprised of a blend of thermoplastic fibers, for example Dacron and other textile fibers, either natural fibers such as cotton, or synthetic fibers such as nylon. These blends and the relative ratio of the thermoplastic and textile fibers may cover a wide range.

While a particular embodiment of the present invention has been illustrated and described herein, it is not intended to limit the invention to such disclosure, and changes and modifications may be made therein within the scope of the following claims.

I claim:

1. A method of finishing fabric comprised of yarns including at least some thermoplastic fibers treated in a liquid at a temperature where the thermoplastic fibers tend to set in an angularly deformed condition and where the fabric tends to wrinkle consisting of the steps of freely suspending the fabric, subjecting the suspended fabric to a drying medium and controlling the condition of the drying medium so that its wet bulb temperature is higher than the temperature of the liquid in which the fabric was treated and its dry bulb temperature is higher than the wet bulb temperature whereby the fabric is finished to a wrinkle-free condition.

2. A method of finishing fabric comprised of yarns including at least some thermoplastic fibers treated in a liquid at a temperature where the thermoplastic fibers tend to set in an angularly deformed condition and where the fabric tends to wrinkle consisting of the steps of freely suspending the fabric, conveying the suspended fabric through a substantially enclosed drying chamber, circulating a drying medium through the fabric at a rate to cause agitation thereof and controlling the condition of the drying medium so that its wet bulb temperature is higher than the temperature of the liquid in which the fabric was treated and its dry bulb temperature is higher than the wet bulb temperature whereby the fabric is finished to a wrinkle-free condition.

3. A method of finishing fabric comprised of yarns including at least some thermoplastic fibers treated in a liquid at a temperature where the thermoplastic fibers tend to set in an angularly deformed condition and where the fabric tends to wrinkle consisting of the steps of freely suspending the fabric, conveying the suspended fabric through a substantially enclosed drying chamber, circulating a drying medium through the drying chamber, controlling the condition of the drying medium circulated through the drying chamber so that its Wet bulb temperature is higher than the temperature of the liquid in which the fabric was treated and its dry bulb temperature is higher than the wet bulb temperature, and maintaining the fabric in the drying chamber a predetermined length of time sufficient to raise the temperature of the fabric approximately to the dry bulb temperature of the drying medium whereby the bound and free moisture therein is removed and the fabric is finished to a substantially wrinkle-free condition.

4. A method of finishing fabric comprised of yarns including at least some thermoplastic fibers treated in a liquid at a temperature where the thermoplastic fibers tend to set in an angularly deformed condition and where the fabric tends to wrinkle consisting of the steps of freely suspending the fabric, conveying the suspended fabric through a substantially enclosed drying chamber, circulating a drying medium through the drying chamber,

adding heat and moisture to the drying medium circulated through the drying chamber, sensing the dry bulb and wet bulb temperature of the drying medium prior to circulation thereof through the drying chamber and selectively varying the amount of heat and moisture added to the drying medium to maintain the wet bulb temperature thereof higher than the temperature of the liquid in which the fabric was treated and its dry bulb temperature higher than the wet bulb temperature whereby the fabric is finished to a substantially wrinkle-free condition.

5. A method of finishing garments comprised of yarns including at least some thermoplastic fibers treated in a liquid at a temperature where the thermoplastic fibers tend to set in an angularlydeformed condition and v where the fabric tends to wrinkle consisting of the steps of freely suspending the garment, conveying the garment through a substantially enclosed drying chamber, circulating a drying medium upwardly through the garment at a rate to cause agitation and ballooning thereof and controlling the condition of the drying medium so that its wet bulb temperature is higher than the temperature of the liquid in which the garment was treated and its dry bulb temperature is higher than the wet bulb temperature whereby the garment is finished to a wrinkle-free condition.

6. A method of finishing fabric comprised of yarns including at least some thermoplastic fibers moisture treated at a temperature Where the thermoplastic fibers tend to set in an angularly deformed condition and where the fabric tends to wrinkle consisting of the steps of freely suspending the fabric, subjecting the suspended fabric to'a drying medium and controlling the condition of the drying medium so that its wet bulb temperature is higher than the temperature at which the fabric was moisture treated and its dry bulb temperature is higher than the wet bulb temperature whereby the fabric is finished to a wrinkle-free condition.

7. A method of finishing fabric comprised of yarns including at least some thermoplastic fibers treated in a liquid at a temperature of at least approximately F., consisting of the steps of freely suspending the fabric, subjecting the suspended fabric to a drying medium and controlling the condition of the drying medium so that its wet bulb tempera-ture is higher than the temperature of the liquid in which the fabric was treated and its dry bulb temperature is higher than the wet bulb temperature whereby the fabric is finished to a wrinkle-free condition.

References Cited by the Examiner UNITED STATES PATENTS 2,365,890 12/1944 McBean 34-46 X 2,606,372 8/1952 Foulder et a1. 34-46 2,654,162 10/1953 Long et a1. 34-46 X 2,698,488 1/1955 Cannon et a1. 3446 X 3,102,796 9/1963 Erickson 34--216 X 3,131,034 4/1964 Marsh 3430 FREDERICK L. MATTESON, ]R., Primary Examiner.

WILLIAM F. ODEA, Examiner.

F D. A. TAMBURRO, Assistant Examiner. 

1. A METHOD OF FINISHING FABRIC COMPRISED OF YARNS INCLUDING AT LEAST SOME THERMOPLASTIC FIBERS TREATED IN A LIQUID AT A TEMPERATURE WHERE THE THERMOPLASTIC FIBERS TEND TO SET IN AN ANGULARLY DEFORMED CONDITION AND WHERE THE FABRIC TENDS TO WRINKLE CONSISTING OF THE STEPS OF FREELY SUSPENDING THE FABRIC, SUBJECTING THE SUSPENDED FABRIC TO A DRYING MEDIUM AND CONTROLLING THE CONDITION OF THE DRYING MEDIUM SO THAT ITS WET BULB TEMPERATURE IS HIGHER THAN THE TEMPERATURE OF THE LIQUID IN WHICH 